The index closed 4.64 points lower after gaining 3.08 points in the previous session.
Trading on the Ho Chi Minh Stock Exchange increased by 7% to VND11.173 trillion (US$455.2 million).
The VN-30 basket, comprising the 30 largest capped stocks, saw 18 tickers fell.
VNM of dairy giant Vinamilk saw the biggest drop of 2.4%, followed by GAS of state-owned Petrovietnam Gas with a 2.3% decline and MSN of conglomerate Masan Group, down 1.2%.
Ten blue chips gained. VRE of retail real estate arm Vincom Retail went up 1.6%, SSB of SeABank closed 1.3% higher, and SAB of brewer Sabeco increased by 1.26%.
Foreign investors were net seller to the tune of VND73 billion, mainly selling VHM of property giant Vinhomes and MWG of electronics retail chain Mobile World.
The HNX-Index for stocks on the Hanoi Stock Exchange, home to mid and small caps, rose 0.22%, while the UPCoM-Index for the Unlisted Public Companies Market went up 0.28%.
Global shares rose for a fifth day on Friday, up 0.2%, thanks to gains in Europe, where the STOXX 600 rallied 0.4%, heading for a weekly gain of 2.6%, the most in a month, Reuters reported.
Spot gold was up 0.1% at $2,360.95 per ounce after hitting a two-week high in the previous session. Bullion gained over 1% so far for the week.
MSCI's broadest index of Asia-Pacific shares outside Japan rallied 0.53%.